4 0 Rockwell RS21230 Rear Differential for a Rockwell RS-21-230 $1,350 USD Good used Rockwell RS-21-230 2 speed rear, rear differential assembly. 5.86/8.15 ratio. 90 day guarantee for swap or refund ConditionUsedFits To Make(s)ROCKWELLFits To Model(s)RS-21-230Stock NumberRyd RS-21-230/5.86- MLS Number13478979CategoryDifferentials, Rear Last Updated7/30/2025 LocationFitchburg, MA, US Sold ByRydemore Heavy Duty Truck Parts (888) 519-___ SHOWNUMBERCall Seller Email Seller Save More Info